Re: [LKP] [mm] ac5b2c1891: vm-scalability.throughput -61.3% regression

From: Linus Torvalds
Date: Mon Dec 03 2018 - 13:01:42 EST


On Wed, Nov 28, 2018 at 8:48 AM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Nov 27, 2018 at 7:20 PM Huang, Ying <ying.huang@xxxxxxxxx> wrote:
> >
> > In general, memory allocation fairness among processes should be a good
> > thing. So I think the report should have been a "performance
> > improvement" instead of "performance regression".
>
> Hey, when you put it that way...
>
> Let's ignore this issue for now, and see if it shows up in some real
> workload and people complain.

Well, David Rientjes points out that it *does* cause real problems in
real workloads, so it's not just this benchmark run that shows the
issue.

So I guess we should revert, or at least fix. David, please post your
numbers again in public along with your suggested solution...

Linus